Lymph movement. The overall speed of the flow of lymph The movement of lymph in the human body

If we talk about the work of the body and in particular about the fluids that flow in the body, then not many people immediately call lymph.

However, lymph has great importance for the body and has very significant functions that allow the body to function normally.

What is the lymphatic system?

Many people know about the body's need for blood circulation and the work of other systems, but not many people know about the high importance of the lymphatic system. If the lymph does not circulate through the body for only a couple of hours, then such an organism can no longer function.

Thus, every human body experiences continuous need in the functioning of the lymphatic system.

It is easiest to compare the lymphatic system with the circulatory system and isolate the following differences:

openness, unlike the circulatory system, the lymphatic system is open, that is, there is no circulation as such.
Unidirectional If the circulatory system provides movement in two directions, then the lymph moves in the direction only from the peripheral to the central parts of the system, that is, the fluid first collects in the smallest capillaries and then moves into larger vessels, and the movement goes only in this direction.
There is no central pump. In order to ensure the movement of fluid in the right direction, only a system of valves is used.
More slow motion fluid compared to the circulatory system.
The presence of special anatomical elements- lymph nodes that perform a significant function and are a kind of warehouse for lymphocytes.

The lymphatic system is of the greatest importance for metabolism and for provide immunity. It is in the lymph nodes that the bulk of the foreign elements that enter the body are processed.

If any virus appears in the body, then it is in the lymph nodes that work begins to study and expel this virus from the body.

You yourself can notice this activity when you have, which indicate the body's fight against the virus. In addition, lymph regularly cleanses the body and removes unnecessary elements from the body.

Learn more about the lymphatic system from the video:

Functions

If we talk in more detail about the functions, then it should be noted the connection of the lymphatic system with the cardiovascular system. It is thanks to the lymph that delivery of various items, which cannot be immediately in the cardiovascular system:

proteins;
fluid from the tissue and interstitial space;
fats, which come primarily from the small intestine.

These elements are transported to the venous bed and thus end up in the circulatory system. Further, these components can be removed from the body.

At the same time, many inclusions that are unnecessary for the body are processed at the stage of lymph, in particular, we are talking about viruses and infections that neutralized by lymphocytes and destroyed in the lymph nodes.

It should be noted the special function of the lymphatic capillaries, which are larger in comparison with the capillaries of the circulatory system and have thinner walls. Due to this, from the interstitial space to the lymph proteins and other components can be supplied.

Additionally, the lymphatic system can be used to cleanse the body, since the intensity of the flow of lymph largely depends on the compression of blood vessels and muscle tension.

Thus, massage and physical activity can make the movement of lymph more efficient. Thanks to this, additional cleansing and healing of the body becomes possible.

Peculiarities

Actually the word "lymph" comes from the Latin "lympha", which translates as moisture or clean water. Only from this name it is possible to understand a lot about the structure of the lymph, which washes and cleanses the entire body.

Many could observe lymph, since this liquid exudes on the surface of wounds on the skin. Unlike blood, the liquid is almost completely transparent.

According to the anatomical structure, lymph belongs to connective tissue and contains a large number of lymphocytes in the complete absence of erythrocytes and platelets.

In addition, lymph, as a rule, contains various waste products of the body. In particular, the previously noted large protein molecules that cannot be absorbed into the venous vessels.

Such molecules are often may be viruses therefore, the lymphatic system is used to absorb such proteins.

The lymph may contain various hormones that are produced by the endocrine glands. From the intestines, fats and some other nutrients come here, from the liver - protein.

Direction of lymph flow

The figure below shows a diagram of the movement of lymph in the human lymphatic system. It does not display every lymph vessel and all of the lymph nodes that about five hundred in the human body.

Pay attention to the direction of travel. Lymph moves from the periphery to the center and from the bottom up. Fluid flows from small capillaries, which then join into larger vessels.

The movement goes through the lymph nodes, which contain a huge number of lymphocytes and purify the lymph.

Usually to the lymph nodes more vessels come in than leave, that is, lymph enters through many channels, and leaves one or two. Thus, the movement continues to the so-called lymphatic trunks, which are the largest lymphatic vessels.

The largest is the thoracic duct., which is located near the aorta and passes lymph through itself from:

all organs that are located below the ribs;
left side of chest and left side of head;
left hand.

This duct connects with left subclavian vein, which you can see marked in blue in the picture on the left side. This is where the lymph from the thoracic duct enters.

It should also be noted right duct, which collects fluid from the right upper side of the body, in particular from the chest and head, arms.

From here, lymph enters right subclavian vein, which is located in the figure symmetrically to the left. Additionally, it should be noted such large vessels that belong to the lymphatic system as:

right and left jugular trunks;
left and right subclavian trunks.

It should be said about the frequent location of the lymphatic vessels along the blood, in particular venous vessels. If you look at the picture, you will see some the similarity of the arrangement of the vessels of the circulatory and lymphatic systems.

The lymphatic system has great importance for the human body.

Many doctors consider lymph analysis to be no less relevant than a blood test, since it is lymph that can indicate some factors that are not found in other tests.

In general, lymph, in combination with blood and intercellular fluid, constitutes the internal liquid medium in the human body.

Lymph circulation is the movement of lymph through the lymphatic vessels and capillaries. The main condition that ensures the movement of lymph (see) through the lymphatic capillaries into the large lymphatic vessels and then into the venous bed is a constant influx of fluid from the tissue spaces (see), which creates pressure in the capillaries (see). Of great importance for lymphatic circulation is the physiological activity of individual organs, the contractility of the walls: lymphatic vessels, pulse movements of arterial vessels, etc.

Lymph circulation disorders are observed in various pathological conditions. states and, as a rule, are a consequence of previous diseases. Violations of lymphatic circulation are manifested in a change in the qualitative composition of the lymph, an increase in its quantity. The nature of the change in the qualitative composition of the lymph depends on the pathological process in the tissue area or organ from which the lymph flows. So, with a tumor, tumor cells are present in the lymph, and with inflammation, significant amounts of leukocytes and. A pathological increase in the amount of lymph is a consequence of obstacles in the way of its outflow or an increase in its production (lack of lymph circulation). Distinguish mechanical insufficiency of lymphatic circulation that occurs when the lymphatic vessels are blocked by "fibrinous" blood clots formed as a result of the inflammatory process, when the vessels are compressed by a nearby tumor, etc., and dynamic insufficiency associated with an increase in blood capillaries, which leads to a significant increase in the amount of tissue fluid, which does not have time to flow through the lymphatic vessels. In addition, there is a resorption insufficiency of lymphatic circulation, which occurs when the absorption capacity of the lymphatic capillaries is impaired. Disorders of lymphatic circulation are clinically expressed in an increase and swelling of the affected organ, sometimes lymphatic vessels and lymph outflow occur (lymphorrhagia, lymphorrhea). The most common x-ray method for studying lymphatic circulation (see).

Lymph circulation is the circulation of lymph and tissue fluid in the body. The true internal environment for all cells of the body is tissue fluid (see), through which the exchange of substances between blood and tissues is carried out. Lymph circulation, which together with blood circulation determines the constant renewal of tissue fluid, plays a huge role in the metabolism of the cells of the whole organism.

Lymph circulation consists of: 1) the formation of tissue fluid by blood capillaries and organ tissues; 2) receipt of excess tissue fluid from the intercellular spaces into the system of lymphatic capillaries; 3) movement of lymph (see) through the lymphatic vessels (see) to the lymph nodes (see); 4) the flow of lymph through the main lymphatic ducts [thoracic duct (see), right lymphatic duct] into the large venous vessels of the neck.

The flow of tissue fluid through the endothelium of the lymphatic capillaries occurs when the value of its filtration from the arterial part of the blood capillary into the interstitial spaces prevails over reabsorption in the venous part of the same capillary. For example, with the active activity of an organ (muscle), the level of blood pressure in the arterial section of the capillary rises sharply and there is a continuous accumulation of tissue fluid. An increase in its pressure in the intercellular spaces leads to a continuous flow of tissue fluid into the cavity of the lymphatic capillaries.

The movement of lymph through the lymphatic vessels is due to: a higher level of lymph pressure in the lymphatic capillaries than in the thoracic duct and large veins; the presence in the lymphatic vessels of a large number of valves that prevent the movement of lymph in a retrograde direction; contractions of the surrounding skeletal muscles, as well as peristaltic movements of the intestine, contractions of the heart muscle, pulsation of large arteries. In some organs (the mesentery), own peristaltic movements of the lymphatic vessels were also found.

The study of lymph circulation is carried out by X-ray (injection of contrast agents) and radiological (introduction of radioactive isotopes) methods, as well as vivisection experiments (using cannulas inserted into the thoracic duct and the introduction of vital dyes on the periphery).

Lymph circulation disorders (ascites, edema) are often accompanied by circulatory disorders (with cardiac insufficiency), as well as some metabolic pathologies (myxedema). The formation of edema during inflammation is due to the cessation of the outflow of lymph from the focus of inflammation. Lymphostasis in this case is explained by a spasm of the lymphatic vessels distant from the focus of inflammation, and their thrombosis in the area of the focus.

The fluid that enters the tissue is lymph. The lymphatic system is an integral part of the vascular system, providing the formation of lymph and lymph circulation.

Lymphatic system - a network of capillaries, vessels and nodes through which lymph moves in the body. Lymphatic capillaries are closed at one end, i.e. blindly end in tissues. Lymphatic vessels of medium and large diameter, like veins, have valves. Lymph nodes are located along their course - "filters" that trap viruses, microorganisms and the largest particles in the lymph.

The lymphatic system begins in the tissues of organs in the form of an extensive network of closed lymphatic capillaries that do not have valves, and their walls are highly permeable and have the ability to absorb colloidal solutions and suspensions. Lymphatic capillaries pass into lymphatic vessels equipped with valves. Thanks to these valves, which prevent the reverse flow of lymph, it flows only towards the veins. Lymphatic vessels flow into the lymphatic thoracic duct, through which lymph flows from 3/4 of the body. The thoracic duct drains into the cranial vena cava or jugular vein. Lymph through the lymphatic vessels enters the right lymphatic trunk, which flows into the cranial vena cava.

Rice. Diagram of the lymphatic system

Functions of the lymphatic system

The lymphatic system performs several functions:

The protective function is provided by the lymphoid tissue of the lymph nodes, which produces phagocytic cells, lymphocytes and antibodies. Before entering the lymph node, the lymphatic vessel divides into small branches that pass into the sinuses of the node. Small branches also depart from the node, which are combined again into one vessel;
the filtration function is also associated with the lymph nodes, in which various foreign substances and bacteria are mechanically retained;
the transport function of the lymphatic system is that through this system the main amount of fat that is absorbed in the gastrointestinal tract enters the bloodstream;
the lymphatic system also performs a homeostatic function, maintaining the constancy of the composition and volume of the interstitial fluid;
The lymphatic system performs a drainage function and removes excess tissue (interstitial) fluid located in the organs.

The formation and circulation of lymph ensure the removal of excess extracellular fluid, which is created due to the fact that filtration exceeds the reabsorption of fluid into the blood capillaries. Such drainage function The lymphatic system becomes apparent if the outflow of lymph from some area of the body is reduced or stopped (for example, when squeezing the limbs with clothing, blockage of the lymphatic vessels during their injury, crossing during a surgical operation). In these cases, local tissue edema develops distal to the compression site. This type of edema is called lymphatic.

Return to the bloodstream of albumin, filtered into the intercellular fluid from the blood, especially in organs with highly permeable (liver, gastrointestinal tract). More than 100 g of protein returns to the bloodstream per day with lymph. Without this return, the loss of protein in the blood would be irreplaceable.

Lymph is part of the system that provides humoral connections between organs and tissues. With its participation, the transport of signaling molecules, biologically active substances, and some enzymes (histaminase, lipase) is carried out.

In the lymphatic system, the processes of differentiation of lymphocytes transported by the lymph along with immune complexes that perform body's immune defense functions.

Protective function The lymphatic system also manifests itself in the fact that foreign particles, bacteria, remnants of destroyed cells, various toxins, and also tumor cells are filtered out, captured and in some cases neutralized in the lymph nodes. With the help of lymph, red blood cells that have left the blood vessels are removed from the tissues (in case of injuries, damage to blood vessels, bleeding). Often, the accumulation of toxins and infectious agents in the lymph node is accompanied by its inflammation.

Lymph is involved in the transport of chylomicrons, lipoproteins and fat-soluble substances absorbed in the intestine into the venous blood.

Lymph and lymph circulation

Lymph is a blood filtrate formed from tissue fluid. It has an alkaline reaction, it is absent, but contains fibrinogen and, therefore, it is able to coagulate. The chemical composition of lymph is similar to that of blood plasma, tissue fluid and other body fluids.

Lymph flowing from different organs and tissues has a different composition depending on the characteristics of their metabolism and activity. The lymph flowing from the liver contains more proteins, the lymph contains more. Moving along the lymphatic vessels, the lymph passes through the lymph nodes and is enriched with lymphocytes.

Lymph - a clear, colorless liquid contained in the lymphatic vessels and lymph nodes, in which there are no erythrocytes, there are platelets and many lymphocytes. Its functions are aimed at maintaining homeostasis (the return of protein from tissues to the blood, the redistribution of fluid in the body, the formation of milk, participation in digestion, metabolic processes), as well as participation in immunological reactions. The lymph contains protein (about 20 g/l). Lymph production is relatively low (most of all in the liver), about 2 liters are formed per day by reabsorption from the interstitial fluid into the blood of the blood capillaries after filtration.

Lymph formation due to the transition of water and dissolved substances from the blood capillaries to the tissues, and from the tissues to the lymphatic capillaries. At rest, the processes of filtration and absorption in the capillaries are balanced and the lymph is completely absorbed back into the blood. In the case of increased physical activity in the process of metabolism, a number of products are formed that increase the permeability of capillaries for protein, its filtration increases. Filtration in the arterial part of the capillary occurs when the hydrostatic pressure rises above the oncotic pressure by 20 mm Hg. Art. During muscular activity, the volume of lymph increases and its pressure causes the penetration of interstitial fluid into the lumen of the lymphatic vessels. Lymph formation is facilitated by an increase in the osmotic pressure of tissue fluid and lymph in the lymphatic vessels.

The movement of lymph through the lymphatic vessels occurs due to the suction force of the chest, contraction, contraction of the smooth muscles of the wall of the lymphatic vessels and due to the lymphatic valves.

Lymphatic vessels have sympathetic and parasympathetic innervation. Excitation of the sympathetic nerves leads to a contraction of the lymphatic vessels, and when the parasympathetic fibers are activated, the vessels contract and relax, which increases the lymph flow.

Adrenaline, histamine, serotonin increase the flow of lymph. A decrease in the oncotic pressure of plasma proteins and an increase in capillary pressure increase the volume of outflowing lymph.

Formation and amount of lymph

Lymph is a fluid that flows through the lymphatic vessels and is part of the internal environment of the body. The sources of its formation are filtered from the microvasculature into the tissues and the contents of the interstitial space. In the section on microcirculation, it was discussed that the volume of blood plasma filtered into tissues exceeds the volume of fluid reabsorbed from them into the blood. Thus, about 2-3 liters of blood filtrate and fluid of the intercellular medium that are not reabsorbed into the blood vessels per day enter the lymphatic capillaries, the system of lymphatic vessels through the interendothelial clefts, and return to the blood again (Fig. 1).

Lymphatic vessels are present in all organs and tissues of the body with the exception of the superficial layers of the skin and bone tissue. The largest number of them is found in the liver and small intestine, where about 50% of the total daily volume of the body's lymph is formed.

The main constituent of lymph is water. The mineral composition of the lymph is identical to the composition of the intercellular environment of the tissue in which the lymph was formed. Lymph contains organic substances, mainly proteins, glucose, amino acids, free fatty acids. The composition of the lymph flowing from different organs is not the same. In organs with a relatively high permeability of blood capillaries, such as the liver, lymph contains up to 60 g/l of protein. The lymph contains proteins involved in the formation of blood clots (prothrombin, fibrinogen), so it can clot. The lymph flowing from the intestines contains not only a lot of protein (30-40 g/l), but also a large amount of chylomicrons and lipoproteins formed from aponrotheins and fats absorbed from the intestines. These particles are in suspension in the lymph, transported by it into the blood and give the lymph a similarity to milk. In the composition of the lymph of other tissues, the protein content is 3-4 times less than in the blood plasma. The main protein component of tissue lymph is the low molecular weight fraction of albumin, which is filtered through the wall of capillaries into extravascular spaces. The entry of proteins and other large molecular particles into the lymph of the lymphatic capillaries is carried out due to their pinocytosis.

Rice. 1. Schematic structure of a lymphatic capillary. The arrows show the direction of lymphatic flow.

Lymph contains lymphocytes and other forms of white blood cells. Their number in different lymphatic vessels varies and is in the range of 2-25 * 10 9 / l, and in the thoracic duct is 8 * 10 9 / l. Other types of leukocytes (granulocytes, monocytes and macrophages) are contained in the lymph in a small amount, but their number increases with inflammatory and other pathological processes. Red blood cells and platelets can appear in the lymph when blood vessels are damaged and tissue injuries.

Absorption and movement of lymph

Lymph is absorbed into the lymphatic capillaries, which have a number of unique properties. Unlike blood capillaries, lymphatic capillaries are closed, blindly ending vessels (Fig. 1). Their wall consists of a single layer of endothelial cells, the membrane of which is fixed with the help of collagen filaments to extravascular tissue structures. Between endothelial cells there are intercellular slit-like spaces, the dimensions of which can vary widely: from a closed state to a size through which blood cells, fragments of destroyed cells and particles comparable in size to blood cells can penetrate into the capillary.

The lymphatic capillaries themselves can also change their size and reach a diameter of up to 75 microns. These morphological features of the structure of the walls of the lymphatic capillaries give them the ability to change the permeability over a wide range. Thus, during contraction of skeletal muscles or smooth muscles of internal organs, due to the tension of collagen filaments, interendothelial gaps can open, through which the intercellular fluid, the mineral and organic substances contained in it, including proteins and tissue leukocytes, freely move into the lymphatic capillary. The latter can easily migrate into the lymphatic capillaries also due to their ability to amoeboid movement. In addition, lymphocytes, which are formed in the lymph nodes, enter the lymph. The flow of lymph into the lymphatic capillaries is carried out not only passively, but also under the influence of negative pressure forces that arise in the capillaries due to the pulsating contraction of the more proximal parts of the lymphatic vessels and the presence of valves in them.

The wall of the lymphatic vessels is built of endothelial cells, which, on the outside of the vessel, are covered in the form of a cuff by smooth muscle cells located radially around the vessel. Inside the lymphatic vessels there are valves, the structure and principle of functioning of which are similar to the valves of the venous vessels. When smooth myocytes are relaxed and the lymphatic vessel is dilated, the valve leaflets open. With the contraction of smooth myocytes, which causes narrowing of the vessel, the pressure of the lymph in this area of the vessel increases, the valve flaps close, the lymph cannot move in the opposite (distal) direction and is pushed through the vessel proximally.

Lymph from the lymphatic capillaries moves into postcapillary and then into large intraorgan lymphatic vessels that flow into the lymph nodes. From the lymph nodes, through small extraorganic lymphatic vessels, lymph flows into larger extraorganic vessels that form the largest lymphatic trunks: the right and left thoracic ducts, through which lymph is delivered to the circulatory system. From the left thoracic duct, lymph enters the left subclavian vein near its junction with the jugular veins. Most of the lymph moves into the blood through this duct. The right lymphatic duct delivers lymph to the right subclavian vein from the right side of the chest, neck, and right arm.

Lymph flow can be characterized by volumetric and linear velocities. The volumetric flow rate of lymph from the thoracic ducts to the veins is 1-2 ml / min, i.e. only 2-3 l / day. The linear speed of lymph movement is very low - less than 1 mm/min.

The driving force of the lymph flow is formed by a number of factors.

The difference between the hydrostatic pressure of the lymph (2-5 mm Hg) in the lymphatic capillaries and its pressure (about 0 mm Hg) at the mouth of the common lymphatic duct.
Contraction of smooth muscle cells in the walls of lymphatic vessels that move lymph towards the thoracic duct. This mechanism is sometimes called the lymphatic pump.
Periodic increase in external pressure on the lymphatic vessels, created by contraction of the skeletal or smooth muscles of the internal organs. For example, the contraction of the respiratory muscles creates rhythmic pressure changes in the chest and abdominal cavities. The decrease in pressure in the chest cavity during inhalation creates a suction force that promotes the movement of lymph into the thoracic duct.

The amount of lymph formed per day in a state of physiological rest is about 2-5% of body weight. The rate of its formation, movement and composition depend on the functional state of the organ and a number of other factors. Thus, the volumetric flow of lymph from the muscles during muscular work increases by 10-15 times. After 5-6 hours after eating, the volume of lymph flowing from the intestine increases, its composition changes. This occurs mainly due to the entry of chylomicrons and lipoproteins into the lymph.

Clamping the veins of the legs or standing for a long time leads to difficulty in returning venous blood from the legs to the heart. At the same time, the hydrostatic pressure of blood in the capillaries of the extremities increases, filtration increases and an excess of tissue fluid is created. The lymphatic system under such conditions cannot provide sufficient drainage function, which is accompanied by the development of edema.

Approximately 100 ml of lymph flows through the thoracic duct of a person at rest in one hour, and approximately 20 ml of lymph enters the circulation every hour through other channels, so the total lymph flow detected is about 120 ml per hour.

This is 1/120,000 of the calculated rate of fluid diffusion back and forth through the membranes of the capillaries, and it is a tenth of the rate of filtration from the arterial ends of the capillaries into the tissue spaces of the whole body.

These facts indicate that the flow of lymph is relatively small compared to the total fluid exchange between plasma and interstitial fluid. Factors that determine the rate of lymph flow. Interstitial fluid pressure.

An increase in interstitial free fluid pressure compared to its normal level of 6.3 mm Hg. increases the rate of flow in the lymphatic capillaries. The increase in flow rate becomes progressively greater as the pressure of the interstitial fluid increases until this pressure value reaches a value slightly greater than 0 mm Hg, in which case the flow rate reaches a maximum, it increases from 10 to 50 times compared to normal.

Thus, some factor (other than the obstruction of the lymphatic system itself) may lead to an increase in interstitial pressure, which increases the speed of lymph flow.

Such factors include: increased capillary flow; reduced osmotic pressure of plasma colloids; increased protein content in the interstitial fluid; increase in capillary permeability.

lymphatic pump. Valves are present in all lymphatic channels into which the lymphatic capillary flows.

In large lymphatic vessels, the valves are located every few millimeters, and in small lymphatic vessels, the valves are located somewhat more often, which indicates a wide distribution of valves. The lymph vessel is compressed under pressure for some reason, the lymph is pushed in both directions, but since the lymph valve is open only in the central direction, the lymph moves in only one direction.

Lymphatic vessels can be compressed either by contraction of the walls of the lymphatic vessel or by pressure from surrounding structures.

Filming of an exposed lymphatic vessel, both in animals and in humans, has shown that if at any time the lymphatic vessel is stretched by fluid, the smooth muscle in the vessel wall automatically contracts.

Further, each segment of the lymphatic vessel between the valves acts as a separate automatic pump. Namely, the filling of the segment causes it to contract and the fluid is pumped through the next valve to the next lymphatic segment.

The next segment is thus filled, and after a few seconds it also contracts; this process continues along the entire lymphatic vessel until the fluid finally expires. In a large lymph node, this lymphatic pump can generate a pressure of 25 to 50 mmHg if the vessel outlet is blocked.

In addition to pumping caused by internal contraction of the walls of the lymphatic vessel, pumping can be caused by other external factors that compress the lymphatic vessel. In order of importance, these factors are: muscle contraction; movement of body parts; arterial pulsations; tissue compression by objects outside the body.

The outflow of lymph from the organ, in general, is the more significant, the more intensively the organ works. If, for example, it is irritated in a dog, then the secretion of the submandibular gland increases, and at the same time, the outflow of lymph from the lymphatic vessels of the gland increases.

One might think that this depends on the simultaneous expansion of the blood vessels in the gland; however, if the gland is poisoned with atropine and then the notochord is irritated, then the outflow of lymph does not increase, despite the fact that the blood supply to the gland increases in exactly the same way as before.

In the same way, one can increase the outflow of lymph from the liver, stimulating an increased production of bile by intravenous injection of sodium taurocholic acid or hemoglobin, or from the pancreas, increasing its secretion by injecting secretin.

Further, already Claude Bernard and Ranke observed that an active gland or an active muscle extracts water from the blood flowing through them. When attempting a physicochemical interpretation of these phenomena, one should first of all take into account that, in general, during the process of metabolism in organs, large molecules are split into numerous small ones, and since osmotic pressure is a function of the number of molecules, due to this, hand in hand with an increase metabolism and an increase in osmotic pressure.

This effect of metabolism can be seen if, for example, both kidneys are cut out from a dog. Since the function of the kidneys is to remove excess molecules from the body in the form of metabolic end products, after extirpation of them, even when the animal is starving, the osmotic pressure of the blood grows and grows, and therefore its freezing point decreases, for example from -0.56 to - 0.75.

Thus, one can imagine as a direct effect of the work of the organs an increased absorption of water from the flowing blood by osmosis.

Subsequently, the organs are freed from this excess water, and in this respect a number of factors must be taken into account, namely, firstly, the turgor of the organs; when the working organs are very filled with tissue water, then their capsules, penetrated by elastic fibers, stretch, strain and thus can press the liquid out (at least under the assumption that the resistance to flow periodically changes).

Secondly, any pressure on the organs from the outside contributes to the flow of lymph, and this is all the more so since there are valves in the lymphatic vessels that, like venous valves, allow flow in only one direction - towards the thoracic duct.

Further, the lymphatic vessels reproduce peristaltic contractions (Geller), which again, together with the valves, ensure the outflow of lymph. Then, with each inhalation movement, the lymph is sucked into the thoracic duct due to an increase in negative pressure in the chest cavity.

Finally, there are local special devices for the movement of lymph. These include smooth muscles contained in the capsule and crossbars of the lymph glands; they can squeeze out the contents of the glands during their contraction.

In the same way, the villi of the intestine, by their rhythmic movements, pump lymph from the central lymphatic vessel to the larger lymphatic vessels of the mesentery, and some animals have special lymphatic hearts as special lymph motors. In a frog, for example, two of these hearts lie on both sides of the sacrum and two above the shoulder girdle.

Heidenhain drew attention to the special chemicals that cause the formation of lymph, the so-called lymphogenous agents. These are substances alien to the body, for example, extracts from leeches, crayfish muscles, shells, strawberries, bacteria, further - tuberculin, peptone, chicken protein, bile. The effect of these funds has not yet been sufficiently analyzed.

There are two types of lymph formation:

1. At zero or even negative interstitial pressure and the absence of interendothelial gaps in the lymphatic capillaries, it is characterized by the diffusion transition of protein and other large molecular compounds into the lymphatic channel in the presence of an appropriate protein concentration gradient between the lymph and interstitial fluid.

2. With a positive interstitial pressure and open interendothelial junctions of the lymphatic capillaries, it is characterized by the transition of the interstitial fluid into the lymphatic channel due to the hydrostatic pressure difference.

Such conditions are typical for hydrated tissues, and the mechanism of lymph formation corresponds to the filtration-resorption theory. The regulation of the lymph formation process is aimed at increasing or decreasing the filtration of water and other elements of the blood plasma (salts, proteins, etc.) by the autonomic nervous system and humoral-vasoactive substances that change blood pressure in arterioles, venules and capillaries, as well as the permeability of vessel walls.

For example, catelhomines (adrenaline and norepinephrine) increase blood pressure in venules and capillaries, thereby increasing fluid filtration into the interstitial space, which enhances lymph formation.

Local regulation is carried out by tissue metabolites and biologically active substances secreted by cells, including the endothelium of blood vessels. Obviously, the lymphatic pump becomes very active during exercise, often increasing lymph flow by 5-15 times.

On the other hand, during rest, the flow of lymph is very weak. Lymphatic capillary pump. Many physiologists suggest that the lymphatic capillary is also capable of pumping lymph, in addition to the lymphatic pump of the large lymphatic vessels. As explained earlier in the chapter, the walls of the lymphatic capillaries are intimately connected to the surrounding cells through their attachment filaments.

Thus, at the time when excess fluid enters the tissue and tissue swelling, the attachment threads cause the lymphatic capillaries to open and fluid flows into the capillary through the junctions between the endothelial cells.

Thus, when the tissue is compressed, the pressure inside the capillary rises and forces the fluid to move in two directions: first, backward, through the openings between the endothelial cells, and second, forward, into the collecting lymphatic vessels.

However, since the edges of endothelial cells normally overlap within the lymphatic capillary, backflow is prevented by overlapping cells over the openings.

Thus, the openings close, they act as one-way valves, and very little fluid flows back into the tissues.

On the other hand, lymph that moves forward into the collecting lymph vessel does not return to the capillary after the compression cycle is completed because many valves in the collecting lymph vessel block any back flow of lymph.

Thus, some factor that causes constriction of the lymphatic capillaries is likely to cause fluid to move in the same way that constriction of large lymph nodes causes the lymph to sway.

The part of the vascular system that frees the tissues of the body from metabolic products, infectious agents and their toxins is called the lymphatic. It contains vessels, nodes, ducts, as well as organs involved in the formation of lymphocytes.

With insufficient immune protection, tumor and microbial cells can spread along the lymphatic pathways. Stagnation of lymph leads to the accumulation of excretory products in the tissues. To improve the drainage function of the lymphatic system, massage and special cleaning methods are prescribed.

Read in this article

The composition of the lymphatic system includes capillary, intraorganic and stem vessels, nodes and lymphatic organs.

Vessels

Inside the organs there is a network of small lymphatic capillaries, they have very thin walls through which large particles of protein and liquid easily penetrate from the intercellular space. In the future, they are combined into vessels similar to veins, but with more permeable membranes and a developed valve apparatus.

Vessels from the organs carry lymph to the nodes. In appearance, the lymphatic network is similar to beads. Such a structure arises due to the alternation of areas of narrowing and expansion at the site of attachment of the semilunar valves. The penetration of tissue fluid into the capillaries is explained by the difference in osmotic pressure (the lymph is more concentrated), and the reverse flow is impossible due to the valves.

Knots

They have many incoming vessels and 1 or 2 outgoing vessels. The shape is similar to a bean or a ball about 2 cm. They filter the lymphatic fluid, linger and inactivate toxic substances and microbes, and the lymph is saturated with cells of the immune system - lymphocytes.

The fluid that moves through the lymphatic vessels has a whitish or yellowish color. Its composition depends on the organ from which it comes.

The following elements penetrate into the lymph:

water;
proteins (large molecules);
destroyed and tumor cells;
bacteria;
particles of dust and smoke from the lungs;
fluid from the abdominal cavity, pleura and pericardium, joints;
any foreign particles.

Basic functions in the body

The biological role of the lymphatic system is associated with the following activities:

the formation of lymphocytes responsible for cellular and humoral (with the help of special blood proteins) immunity;
delay in the lymph node of mechanical impurities, microbes and toxic compounds;
return to the venous vessels of purified blood;
transfer of fats from the intestinal lumen to the blood;
additional tissue drainage to reduce swelling;
absorption from the tissue fluid of large protein molecules, which themselves cannot enter the blood vessels due to their size.

Watch the video about the human lymphatic system and its functions:

Lymph movement pattern

The initial absorption of tissue fluid occurs in the organs by lymphatic capillaries. The resulting lymph through the network of vessels enters the nodes. Purified and saturated with lymphocytes, the fluid from the lymph node moves into the trunks and ducts. There are only two of them in the body:

chest - collects lymph from the left upper limb, the left side of the head, chest and all parts of the body lying under the diaphragm;
right - contains fluid from the right arm, half of the head and chest.

The ducts carry lymph to the left and right subclavian veins. It is at the level of the neck that the lymphovenous anastomosis is located, through which the penetration of the lymphatic fluid into the venous blood passes.

For the promotion of lymph, the simultaneous action of the following factors is required:

the pressure of the fluid that is formed continuously;
contraction of the smooth muscles of the vessels between the two valves - the muscular cuff (lymphangion);
fluctuations in the walls of arteries and veins;
muscle compression during body movements;
suction effect of the chest during breathing.

Organs of the lymphatic system

Lymphoid tissue is found in various structures. They are united by the fact that they all serve as a site for the formation of lymphocytes:

the thymus is located behind the sternum, ensures the maturation and "specialization" of T-lymphocytes;
bone marrow is present in the tubular bones of the limbs, pelvis, ribs, contains immature stem cells, from which blood cells are subsequently formed;
pharyngeal tonsils are located in the nasopharyngeal region, protect against microbes, participate in hematopoiesis;
the appendix departs from the initial section of the large intestine, cleanses the lymph, forms enzymes, hormones and bacteria involved in the digestion of food;
spleen - the largest organ of the lymphatic system, adjacent to the stomach in the left half of the abdominal cavity, acts as a filter for bacteria and foreign particles, produces antibodies, lymphocytes and monocytes, regulates the functioning of the bone marrow;
lymph nodes of internal organs (single or clusters) take part in the formation of cells for immune protection - T and B lymphocytes.

Types and groups of diseases

In diseases of the lymphatic system, inflammatory processes can occur:

lymphangitis - capillaries, vessels and trunks that are in contact with the focus of suppuration are affected;
lymphadenitis - lymph nodes are involved, the infection penetrates with lymph or directly through the skin (mucosa) in case of injuries.

Lesions of the organs of the lymphatic system can manifest as tonsillitis when the tonsils are infected, appendicitis (inflammation of the appendix, appendix). Pathological changes in the thymus lead to muscle weakness, autoimmune processes, tumors.

Violation of the bone marrow causes a variety of changes in the composition of the blood: cell deficiency with a decrease in immunity (), clotting (), oxygen supply (anemia), malignant blood tumors.

Enlargement of the spleen (splenomegaly) occurs in diseases of the blood, liver, typhoid fever. An abscess or cyst may also form in the tissue.

Stagnation of lymph fluid leads to the development of lymphedema (lymph edema). It occurs when there is an obstruction in the vessels of a congenital (structural anomaly) or acquired nature. Secondary lymphedema accompanies injuries, burns, infections, and surgical interventions. With the progression of lymphostasis, elephantiasis of the lower extremities occurs, requiring surgery.

Elephantiasis of the lower extremities

Tumor processes involving lymphatic vessels are more often benign. They are called lymphangiomas. They are found on the skin, in the subcutaneous layer, as well as in places of accumulation of lymphoid tissue - the neck, head, chest, abdominal cavity, inguinal and axillary regions. With malignancy, lymphosarcoma is located in the same areas.

Causes of disorders in the body

Inflammatory and tumor processes occur when the immune system malfunctions, when it ceases to cope with the body's defense function. This may be due to external factors:

unfavorable climatic conditions,
moving (disruption of adaptation),
radiation,
air pollution, water pollution,
nitrates in food
prolonged exposure to the sun
stress.

Chronic foci of infection in the body, as well as a weak function of the excretory organs, contribute to an excessive load on the lymphatic system. The result is a decrease in its essential functions. Of no small importance for the lymphatic flow is the state of the circulatory system, of which the lymphatic system is a part.

Stagnant processes occur in the following pathological conditions:

circulatory failure - arterial (weakness of cardiac activity) and venous (,);
physical inactivity, obesity;
diseases of the kidneys, liver, intestines;
congenital anomalies in the development of the organs of the lymphatic system;
injuries and operations, burns.

Symptoms of the onset of diseases

If the movement of lymph in the lower extremities is disturbed, swelling occurs, especially after intense exercise. If treatment is not carried out at this stage, then tissue edema (lymphedema) becomes dense, there is heaviness in the legs, cramps and soreness.

Inflammatory diseases of the vessels and nodes of the lymphatic system are manifested in the form of regional redness, swelling and thickening of the skin. This is accompanied by high fever, chills and headache. With deep lymphangitis, there are no external manifestations, but the affected area increases in volume due to tissue edema. Lymph nodes with lymphadenitis become painful, dense, they can be easily felt.

Submandibular lymphadenitis

Condition Diagnostics

In order to examine the patency of the lymphatic vessels and the outflow blocking zone, the following methods are used:

X-ray controlled lymphography, CT or MRI determine valvular insufficiency, structural anomalies. A normal lymphogram has the appearance of uneven accumulations of a contrast agent in the form of beads.
Lymphoscintigraphy with technetium allows you to detect foci of radioisotope concentration in the zone of lymph stagnation.
Ultrasound with - areas of vasoconstriction, changes in the nodes.
Computer thermography is used for differential diagnosis with phlegmon, phlebitis and osteomyelitis.
Biopsy of the lymph node - reveals blood tumors, cancer metastases.
Blood tests - with inflammation, leukocytosis is noted, when sowing, it is possible to determine the causative agent of the infection.

If tuberculosis is suspected, tests with tuberculin (Mantoux) and chest x-ray are performed.

Treatment Options

In the initial stages of lymph stagnation, predominantly non-drug methods are used - massage, magnetotherapy, wearing compression stockings. A good effect was obtained from mechanical pneumocompression and laser treatment for diseases of the lymphatic vessels.

With severe lymphedema, appoint:

phlebotonics (Detralex, Cyclo-3-fort, Aescin);
enzymes - Wobenzym, Trypsin;
angioprotectors - Trental, Quercetin;
- Lasix, Trifas (no more than 2 - 3 days).

If there is a threat of sepsis, then ultraviolet blood irradiation can be used. At the stage of resorption or with sluggish inflammation, local compresses, dressings with Dimexide, Dioxidine, Chymotrypsin, and mud treatment are indicated.

The progression of lymphatic stagnation with the formation of elephantiasis of the limbs is treated by laying outflow paths during microsurgical operations.

How to cleanse the lymphatic system

To improve the movement of lymph in the body, traditional medicine, massage techniques are used. An important condition for the prevention of diseases is the motor mode - the load should be at least 30 minutes, the normal walking in nature, breathing exercises have a healing effect.

For the accelerated removal of metabolic products from the body and the neutralization of toxic compounds, use:

sauna (steam room, bath);
bath with warm water and sea salt;
saturation of tissues with clean water;
restriction of dairy, meat products, white bread, starch;
juices from cherries, blackberries, grapes, cranberries;
salad of fresh beets and red cabbage with lemon;
adding parsley and dill, lettuce and fresh garlic to food;
herbal tea from clover, elderflower, nettle (a teaspoon of one of the herbs in a glass of boiling water three times a day);
tincture of echinacea or eleutherococcus 15 drops in the morning;
chicory instead of coffee;
spices - ginger, turmeric, fennel;
instead of sweets - currants, blackberries, lingonberries and blueberries;
Swedish bitter tincture - 10 g of juice from aloe leaves, a tablespoon of wormwood, rhubarb and senna leaves, on the tip of a knife - turmeric and saffron. Pour a liter of vodka and insist for 15 days. Drink a teaspoon with tea.

The impact of massage

Lymphatic drainage is enhanced by the use of strokes on the lymph flow. Since its movement occurs only from the bottom up, then the massage movements should have a similar direction.

In this case, the following changes occur in the tissues:

accelerates the movement of fluid from the tissues into the lymphatic capillaries;
puffiness decreases,
products of metabolic processes are removed faster.

Pressing and squeezing works deeper into soft tissues, and vibration enhances microcirculation. Massage is contraindicated in any acute process in the body, and especially in the presence of a purulent focus, since in these cases, accelerated lymph flow will lead to the spread of the lesion to other organs and tissues.

The lymphatic system has a drainage function, is involved in metabolic processes and the formation of cells of the immune system. In case of overvoltage (due to external factors or against the background of diseases), immunity fails, which contributes to inflammatory or tumor processes.

Antibacterial drugs, venotonics, angioprotectors can be used for treatment. In severe cases, surgery is indicated. To cleanse the lymphatic system, you need to adjust your diet, move as much as possible, drink herbal teas, take a course of lymphatic drainage massage.